SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14910b1ed2b78af559c9b18e346586fc3b84bf853f30aa169ae34326afe76998' 
  AND token = 'uRZYW5GsKc0trhGLtnDaY2vRhiCpmPpgNwNQCRyLj/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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