SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e31a21ca4147690d6fef7d14e54ac3e8017670c8493a886b7824c72c02cec909' 
  AND token = 'dG5+JTLKcOFeBPm5Pr+vJ+sQwyo6yz6QNj1+tKg/zDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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