SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f4fded7179e669461b0da67bbdc630825d5137dac37625bc8ad806ead23dd3e' 
  AND token = 'DPgvYovQPkItrqzu0xqi01O1SfYsseFNFR5hxt9iuxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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