SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e3c0192eb90fd44d43332cbbf7afbc0d691e96866686bd52e19cc325325c5010' 
  AND token = 'NtEH26GnbB2z8pOkX/2scpCivWqIIB2YuMbohX66Iyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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