SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e15a79f0217f818cfa7231d2e4935823b4026d44a84f4e7cfd20a295fd2c2371' 
  AND token = 'imCDDWDdzBGOT1mcOJdRe5DfU0ALY0gudXlHrKyyDUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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