SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d24dd8e4b51a2baa0686580e751cb027976c7aa0395fe56f5eba674a894356' 
  AND token = 'iSVAC1ubIKrsWlxTCI5D4XKXnHcQ6bnMj/R1IJlDoR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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