SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d0f443b7aedbdfd3cb8457e08f60b9c41db41f42f190a988649c25a3adeaa2' 
  AND token = 'K0PRoQ8NuIW8vHFL2ZXbiY5w5gLJAxfpzOqyyUE/Cf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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