SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f41b8dbca9335d21c2cd8e0e08cb0b9399014e57618c64bc2f35755951928a0' 
  AND token = 'smMZI2NTa7fXSTGl1hjb0bDnLPkg5dJmhto3CKECqEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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