SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e169d66287b2087143aaa55c7afd1a5014a516a0a345e18cd67d7dda2f49dce' 
  AND token = 'frJkFWsc43fLJ+Z3VwldvvRx1RA+wKVi3VNRQdypXkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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