SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e252f6fae5e8b8029b2513554f52b076cce495fd00840e440f510a14a1ff818' 
  AND token = 'W4u6TBNrerLrHhPByj2LgvqnzbxMjTG6XDqIdmI2vy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}